1. Field of the Invention
This invention relates to a method of forming a splice between two single-mode optical fibre ends and to splices so formed.
2. Description of Related Art
There are many situations where it is necessary to form low loss joints between optical fibre ends. Such situations occur for example anywhere in a telecommunications network where lengths of optical fibre cable have to be joined together or to line equipment such as exchanges, distribution points, etc. In addition to such joints having to be low loss, that is generally no more than 0.5 dB per joint, preferably no more than 0.2 dB, it is necessary that the joints be of low cost. These two requirements dictate that joints only be made demountable where this is a positive requirement. Non demountable joints are referred to as splices and are formed by fusing or gluing the aligned fibre ends together. The difficulty in making low loss fibre splices is that very precise alignment is required, particularly with single-mode fibres, which typically have an overall diameter of about 125 .mu.m but a light carrying core diameter of only about 8 .mu.m. In order to achieve the desired accuracy of alignment, splicing machines are equipped with micromanipulators capable of providing precise positional adjustment in three dimensions. The resultant bulk of the machines severely limits their use in confined spaces.